By amplifying chemical signals, a process that undergoes a chemical reaction can be detected, even at very low concentrations. Such an amplification process has the potential to provide great utility in any field that requires sensitive and/or fast detection of chemical reactions. For example, such a process could be used to detect microorganisms that cause infection and sickness, chemical or bio-warfare agents, or environmental pollutants.
Currently, there are no processes that provide for sensitive and fast detection of chemical reactions. Current methods are either too slow or not sufficiently sensitive. For example, some detection methods can detect the presence of harmful bacteria over the course of a few hours. However, it is often critical to detect pathogens within a few minutes in order to determine that a patient will have infection. The ability to detect the presence of harmful bacteria before the onset of infection would allow the healing of wounds and burns to occur both faster and with fewer complications. Furthermore, after patients are discharged from the hospital, they become responsible for monitoring their own healthcare, and the symptoms of infection may not be evident to the unskilled patient. Rapid identification of dangerous bacterial strains would allow the prescription of the most appropriate treatment and prevent the overuse of broad-spectrum antibiotics resulting in improved patient outcomes and a reduction in the development of antibiotic resistant strains of bacteria.
Severe burns are a major reason for admission to intensive care units. Currently, patients with total burns over 20% of body surface have a mortality rate of 22%. Although modern antimicrobial therapy has improved the outcome for serious burn patients, infections continue to be a major cause of morbidity and mortality in patients surviving the shock phase of a thermal injury. Despite antibiotic therapy and improved asepsis, often the control of infection is not completely successful. Infection is also one of the main causes of the patient's suffering, poor healing of wounds, extensive tissue destruction, and serious local and systemic complications. Therefore, control of infection in a severely burned patient plays an important role in prognosis, because the onset of serious infection may lead to the patient's death, either directly or through related mechanisms (e.g., the postponement of surgery because of poor general conditions).
Nosocomial infections are of serious concern for hospitals, as many patients are weak or immuno-compromised and susceptible to significant morbidity and mortality. Colonization rates are significantly higher in the hospital setting, both among healthcare workers, and among patients. Moreover, the colonizing organisms in the hospital environment are likely to be resistant to many forms of antimicrobial therapy, due to the strong selective pressure that exists in the nosocomial environment, where antibiotics are frequently used. It is estimated that there are more than 2 million hospital-acquired infections each year that could have been prevented by proper hand washing and rapid detection systems for microbial pathogens. These infections can be deadly to many patients. For example, elderly patients who develop a blood-borne infection due to catheterization have more than a 50% mortality rate. Unfortunately, many symptoms are only evident after the infection is already established.
The possibility that food or waterborne pathogens will be encountered in third world countries or unleashed in a bio-terrorism attack is problematic given the state of current technology. Many common causes of illness are capable of infecting the very young or elderly through contaminated water or food, even at very low concentrations (as few as 10 to 100 cells of Shigella, Salmonella, or E. coli O157:H7 can cause illness or death). A method that provides for early detection of such contaminants would be beneficial since current methods require a lengthy sampling and collection time to properly detect the presence and identity of pathogens. Early detection would reduce the number of food recalls and poor brand recognition (for example, when a processing plant is shut down by the USDA).
In this era of resistant bacteria and bio-weapons, the rapid detection and identification of human pathogens and biological toxins is crucial so that the most appropriate medical response can be implemented. Early detection requires some method of signal amplification, as biological agents can infect in such minute quantities that the agents may go unnoticed by other non-amplified techniques. It would be useful to have a signal amplification method that would surpass existing detection and identification systems in their speed and simplicity.